We reinvestigate the pressure dependence of the crystal structure and
antiferromagnetic phase transition in MnTe2 by the rigorous and reliable
tool of high pressure neutron powder diffraction. First-principles density
functional theory calculations are carried out in order to gain microscopic
insight. The measured N\'eel temperature of MnTe2 is found to show unusually
large pressure dependence of 12 K GPa−1. This gives rise to large
violation of Bloch's rule given by α=dlogVdlogTN=−310≈−3.3, to a α value of -6.0 ± 0.1 for
MnTe2. The ab-initio calculation of the electronic structure and the
magnetic exchange interactions in MnTe2, for the measured crystal structures
at different pressures, gives the pressure dependence of the Ne\'el
temperature, α to be -5.61, in close agreement with experimental
finding. The microscopic origin of this behavior turns to be dictated by the
distance dependence of the cation-anion hopping interaction strength